The concept of code expansion for the general class of multiplexed noise codes comprised of code mate pairs having autocorrelation functions which upon detection provides an impulse autocorrelation function is generally known. In all of the expansion concepts proposed in the prior art, the approaches involved butting, interleaving, partial interleaving, or overlapping of one code mate (code b) with the other code mate (code a) where one of the codes is delayed by a value .tau. in forming each code of a new expanded code pair. A typical example of such techniques is shown and described in U.S. Pat. No. 3,461,451, entitled, "Code Generator To Produce Permutations Of Code Mates", which issued to Frank S. Gutleber, the present inventor, on Aug. 12, 1969. It is to this type of code generation that the present invention pertains.